A motor vehicle can sense a danger or defect arising in the motor vehicle and alarm it to a driver. Generally used alarm methods use a lamp of a gauge or sound. However, such alarm methods have several problems. For the alarm method using a lamp, the driver cannot be immediately aware of change in the lamp of the gauge since the driver's view is directed toward the outside. For the alarm method using sound, it is difficult to recognize the sound because of interference by external noise. Further, the alarm method using sound would be useless to a hearing-impaired person. Thus, as an important matter related to safety, it may be desirable to develop a warning alarm apparatus capable of reliably sensing a danger or defect and alarming it to the driver.
Today's steering wheels include functions to control a motor vehicle, in addition to the simple steering function. For example, a steering wheel may be equipped with various up-to-date functional operating devices such as an audio control switch and a constant speed driving switch. However, there has been no sufficient research on warning a danger through a steering wheel when the danger is sensed.
In this regard, Korean Patent Application Publication No. 2004-0038951 (Title of Invention: Warning Apparatus and Method Using Vibration of Steering Wheel) suggests a warning apparatus and method using vibration of a steering wheel, by which the steering wheel is provided with a vibration motor used for common communication devices. When a warning light for an emergency situation is displayed, the vibration motor operates to increase the user's awareness.